Pornography may fall into more than one genre. Felching is a sexual practice involving the act of orally sucking semen out of the vagina or anus of one partner. Perhaps following the example set by gay pornography, they have become a popular subgenre within heterosexual pornography since the turn of the century, featuring both vaginal and anal ejaculations. Bondage pornography specializes in the depiction of sexual bondage or BDSM activities as photographs, stories, movies, or drawings. The consensual submission of the submissive is sometimes demonstrated to others by symbols indicating his/her belonging to the dominant, such as wearing a collar, special tattoos, piercings, a very short haircut or a bald head. This type of pornography is almost exclusively hentai, as true hermaphroditic humans are not fertile and are not usually found in nature. Such works have also often been subject to censorship and other legal restraints to publication, display or possession. In Japan, point of view pornography is referred to as hamedori . The loose and direct camera work often includes tight shots of the genitalia, unlike some traditional porn. HIV is among the infections that require such direct contact and is therefore very unlikely gay hentai to be transmitted via mammary intercourse. Many transgender people regard the term shemale as offensive, momsex arguing that it mocks or shows a lack of respect towards the gender identity and gender expression of transgender individuals; in this view, the term emphasizes the biological sex of a person and neglects their gender. In these research publications, it is suggested that real female ejaculation is the release of a very scanty, thick, and whitish fluid from the female prostate, while the squirting or gushing shown frequently in pornography is a different phenomenon, the expulsion of clear and abundant fluid, which has been shown to be a diluted fluid from the urinary bladder. The study also found gay boy porn that participants reacted positively to a much wider range of figures than a control group, even rating emaciated figures higher.